Automatic train-stop system



M. F. JONES. AUTOMATIC TRAIN STOP SYSTEM. APPLICATION FILED APR. 9,1919- 1,396,84;7. Patented Nov. 15, 1921. F/y/ m I I WITNESSES:

IINVENTOR Mal/nee Fdonea TT\ORNEY MATIRICE'F. JONES, OF WILKINSBURGi,

VAN IA.

PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURINGCOMPANY,

A CORPORATION OF PENNSYL- AUTOMATIC TRAIN-STOP SYSTEM.

Specification of Letters Patent.

Patented Nov. 15,1921.

} Application filed April 9, 1919. Serial No. 288,749.

To all whom it may concern:

Beit known that I, MAURICE F. JONES, a citizen of the United States, anda resident of VVilkinsburg, in the county of Allegheny and State ofPennsylvania,'have invented a new and useful Improvement in AutomaticTrainrstop Systems, of which the following is a specification.

My invention relates to automatic trainstop systems, and it has for itsobject to provide a reliable, yet relatively simple and inexpensive,system for automatically arresting the movement of a train underpredetermined conditions.

More specifically stated, the object of my invention is to provide aplurality of spaced track magnets that are successively energized as atrain passes into the several blocks, together with a time-elementmechanism carried by the train and dependent upon energization from eachsuccessive track magnet, for preventing the automatic stoppage of thetrain. By time-element mechanism 1 mean to include all devices havingthe characteristic of delayed operation, the delay being, in the presentcase, a function of the distance covered by the train.

From another aspect, the object of my invention is to provide, on atrain, mechanism which, if not affected by an external agency, willcause the train to stop after traveling a predetermined distance,together with a plurality of influencing means, spaced along the trackor roadway, which, provided the track ahead is clear, will act to resetthe mechanism on the train to allow the train to proceed.

Another 'object of my invention is to provide, in conjunction with thesystem of the above-indicated character, means for permitting the trainto proceed at a relatively low speed, irrespective of whether or not thetrack ahead is clear.

Other specific objects of my invention will become evident from thefollowing detailed description taken in conjunction with theaccompanying drawing, wherein Figure 1 is a diagrammatic view of thetrack and supply circuits that are employed in carrying out my presentinvention, and Fig. 2 is a view, partially in elevation and partially insection, of the apparatus carried by the train for cooperation with thecircuits illustrated in Fig. 1, together with a diagrammaticrepresentation of the electrical controlling circuits that are locatedupon the train for the purpose of governing the operation of theillustrated apparatus.

Referring to'Fig. 1, the system shown comprises a track having aplurality of the familiar electrically insulated blocks 1, 2, 3, 1 and5, the direction of traffic being indicated by the arrow and theaccompanying legend. Essentially, each block embodies theparallel-running rails 6 and 7 each of which is suitably insulated fromthe adjacent rails by insulating joints 8 of any wellknown type. Aplurality of track magnets 9 are regularly spaced along the track, andone or more per block may be utilized, as desired. A plurality oftransformers, corresponding in number to the track blocks, have theirprimary windings energized from a suitable alternating current-supplycircuit 11, the secondary windings being connected to the rails 6 and 7of the corresponding blocks, A plurality of track relays 12 normallyoccupy their energized upper position, their actuating coils 13 beingconnected to the track rails, whereby the necessary energy is derivedfrom the secondary winding of the corresponding transformer 10.

However, by reason of the inter-connection of the track magnets 9 withsuccessive track-relay contact members, the magnets are normallydeenergized, that is, whenever the particular block is not occupied by atrain.

As soon as a train enters any block, however, as indicated by the wheels15 in the block 2, the secondary winding of the correspondingtransformer 10 is short-circuited to effect substantial deenergizationof the actuating coil 13 of the corresponding track relay 12.Consequently, a circuit is established from one of the supply conductors11 through conductor 20, contact disk 14, of the relay 12 thatcorresponds to block 2, the relay occupying its lower or deenergizedposition, when circuit is continued through conductor 21, track magnets9 corresponding to the occupied block 2, conductor 22, contact disk 23of the succeeding track relay 12 in its normal or energized upperposition, and conductor 24 to the other supply conductor 11.

In this way, the track magnet corresponding to each block is energizedas long as any vehicle wheels interconnect the rails in that block.However, if the block ahead, 3 in the present instance, should beoccupied by another train, the corresponding track relay 12 would assumeits lower position, by reason of the short circuit of the correspondingtransformer secondary winding. and, there fore, the previously tracedcircuit through the track magnets 9 in block 2 would be interrupted. Inother words, the successive track magnets are energized only when thehome block is oceupied,, while the block ahead is clear.

Referring to Fig. 2, the rails 6 and 7, the track magnets 9. and thevehicle wheels 15, are again illustrated, together with the apparatusthat is carried by, or movable with, the train. Such apparatuscomprises, in general, an impulse-coil device 30, which is locatedwithin the zone of magnetic influence of the successive track magnets 9to energize an impulse relay 31, thereby closing a circuit including abattery 32, or other suitable source of energy, for the purpose ofcontrolling the operation of a timeelement mechanism 33 of theescapement type. A valve 34:, for efiecting application of theair-brakes with which the train is equipped, is adapted to be operatedby the time-element mechanism 33, under conditions to he set forth,unless a centrifugallyoperated device 35, which is driven in accordancewith the vehicle speed prevents the operation of the valve.

Each track magnet 9 is shown as comprising a plurality of energizingcoils 36 that are wound upon the upright arms of a magnetizable yoke 37,the upper ends of which are fastened into plates or disks 38 forfacilitating the transmission of a magnetic impulse to the impulse-coildevice 30. This device comprises a similar magnetizableyoke 39 havingend plates 40. a coil 41 being wound around the yoke and connectedacross the terminals of the actuating coil 42 for the impulse relay 31,which is provided with an upper and a lower contact disk, 44 and 45,respectively, for the purpose of closing certain circuits to bedescribed later.

The time-element mechanism 33 comprises a slidable contact segment orplate l6 that bridges a plurality of control fingers 47 throughout themajor portion of its range of travel. The contact Segn'ient 46 isinsulatedly supported by a suitable arm 48, which is paralleled by arack member 49. to which secured a stem or rod 50 and a piston 51 thatoperates within a suitable cylinder 5:2 and is biased toward theillnstrated right-hand position by means of a coil spring 5 3.

A supply pipe 5t for the cylinder 52 communicates with a controllingvalve 55 of a familiar type, which normally effects communicationbetween the supply pipe 53 and the atmosphere through an exhaust port56.

for the purpose of releasing fluid pressure from the cylinder 52. Thevalve is adapted, upon the energization of its actuating coil 57, toclose the communication just n1cn-' tioned and effect the conveyance offluid pressure from the reservoir, or other suitable source (not shown).through a pipe or passa e 58 to the supply pipe 54, whereby,the piston51 is actuated towards the left in opposition to the spring 53.

The rack member 45 meshes with a gearwheel 60, which is concentricallyrelated to a ratchet wheel 62, mechanical connection between theprovided by a flexible mounted pawl or detent 61. An escapement fork 63engages the ratchet or escapement wheel (52, in accordance withwell-known principles, the. outer end of the fork being provided with aroller 64, while a biasing spring 65 is attached to an intermediatepoint of the main arm of the fork to rotatably move the fork around acentral pivotal point 66. A suitablyconfigured cam 67 is secured to agear-wheel (38, which meshes with a pinion (39 that is shown as mounteddirectly upon the vehicle wheelaxle'. It will be understood. however,that any other suitable means for drivin the cam 67 in accordance withthe vehicle speed may be utilized.

he brake-valve 34 comprises a casing that houses a valve-pin T6 and aplug 77, which is biased to the illustrated closed position by means ofan adjustable spring 78. The valve-pin 76 projects beyond the casing 75in a. position to be engaged by a vertical arm 48 of the time-elementmechanism 33 under conditions to be described.

pipe or passage 79 communicates with the brake-valve 34 and is directlyconnected to the fluid-pressure supply. \Vhcnever the valve-pin T6 isaccuated toward the right by the vertical arm -18". in opposition to thespring 78, fluid pressure i exhausted or bled from the inlet pipe. 7!)through e.\'- haust ports 80 of the valve, whereby the train ainbrakcsare automatically set, in accordance with a familiar operation that neednot be further illustrated or described here.

The centrifugally operated mechanism 35 comprises a shaft that isdriven. in any suitable manner. from the vehicle wheels, a plurality offly-bails 86. and a cooperating linkage device 87 of a wclldmown type,for the purpose of vertically actuating a slidable sleeve 99, which isinterposed in the horizontal path of trawl oi the vertical arm 48 of thetune-element mechanism 33. whenever the vehicle speed is sullicicntlylow to cause the sleeve 88 to assume such an obstructing position. Itwill be understood that the speed at which further niovcincnt of thevertical arm 4s toward the ri -hi is prevented by the sleeve 88. may bereadily gear-wheel and the ratchet being determined by thecharacteristics of the centrifugally operated device, and, inparticular, the length of the sleeve 88. The position of the sleeve issuch that further movement of the escapement mechanism toward the rightis prevented just prior to the engagement of the vertical arm 48 withthe valve-pin 76, whereby setting of the train brakes is automaticallyprevented whenever the vehicle speed is of a predetermined low value.

The operation of the illustrated system may be set forth as follows:When the impulse coil 30 passes an energized track magnet 9, 'a certainimpulse of voltage is induced in the coil to energize the actuating coil42 for the impulse relay 31 and thereby actuate the relay to itsillustrated upper position. A new circuit is thereu on completed fromthe positive terminal 0 the bat tery 32 through upper contact disk 44and actuating coil 42 of the relay, conductor 90, control fingers 47,which are bridged by contact segment 46 of the time-element mechanism33, and conductor 91 to the negative battery terminal. In this way, theimpulse relay 31 is held in its upper or closed position as long as thecontrol fingers 47 are )ridged by the slidable contact segment 46.Another circuit is established, upon the energization of the impulserelay, from the battery 32, through lower relay disk 45, conductor 92,actuating coil 57 of the controlling valve 55, and conductor 91 to thenegative battery terminal. Consequently, the valve 55 is depressed toadmit fluid pressure from the inlet pipe 58 through supply pipe 54 tothe cylinder 52, whereby the piston 51 is actuated toward the left tocause the rack member 49 to rotatably move the gear wheel 60 and theescapement wheel 62 in a counter-clockwise direction. Such movement issubstantially instantaneous, since the inclined surfaces of the'gear-wl1eel teeth slide by the arm of the pawl 61 with practically noobstruction.

The limit of travel of the rack member 49 toward the left is determinedby the length of the 'slidable contact segment 46, since, as soon as thecontrol fingers 47 oc- 'cupy the position marked Reset, corresponding tocomplete disengagement with the segment 46, the actuating coil 42 of theimpulse relay 31 is deenergized, causing the relay to drop to its lowerposition, which, in' turn, deenergizes the actuating coil 57 for thecontrolling valve 55, and thus releases the fluid pressure from theoperating cylinder52. However, although the spring 53 tends to quicklyactuate the piston 51 toward the illustrated right-hand position, suchmovement is prevented by reason of the engagement of the ratchet wheel62 and escapement fork 63.

As the train moves forward, the cam 67 of the cam, and such movement isindependent of the direction of travel of the train. If the traintravels. more than a predetermined distance, dependent upon the gearratio between the gear-wheel 68 and the pinion 69, and also providedthat no energized track magnet 9 is passed, the stepby-step movement ofthe escapement mechanism will proceed to a point wherein the verticalarm 48 engages the valve-pin 76 to bleed the train-line pipe 79 and thusautomatically set the vehicle air-brakes, as previously explained.

However, if, before the brake-setting posi tion of the escapementmechanism 33 is reached, an energized track magnet 9 is passed, then themechanism will be re-set by reason of the passage of a new magneticimpulse from the coil 30, through the relay 31, to close the illustratedcircuits and again permit fluid-pressure to enter the operating cylinder52. Consequently, after each resetting process, the train may againproceed for the abovementioned predetermined distance without the trainbrakes being automatically set.

The reason for the regular or uniform spacing of the track magnets 9will be evident from the foregoing statement, since actuation of thevalve-pin 76 is dependent upon the distance thatthe train travelswithout passing an energized track magnet. However, the track blocksneed not be of uniform length, and, if desired, two or more trackmagnets may be placed in one block.

After the train has been stopped by the above-described mechanism, if itis desired to proceed cautiously into the danger zone. the train crewmay manually re-set the mechanism and release the vehicle brakes bymeans of depressing the illustrated pushbuttons 95 and 96, which areconnected in series relation with the actuating coil 57 for thecontrolling valve 55 across the terminals of the battery 32.Consequently, the concurrent closure of the push-buttons 95 and 96,which are preferably so located that one of them may be closed only bythe engineer and the other only by the fireman, performs the samefunction as the actuation of the contact disk 45 of the relay 31 to itsupper or closed position.

As previously mentioned, it may be desirable, in some cases, to preventthe automatic application of the train brakes, provided the vehicle isproceeding at a relatively low rate of speed. For this purpose, thecentrifugally-operated device 35 interposes itself in the path of thevertical arm 48 of the time-element mechanism 33 just before thevalve-pin 76 is reached, as already set forth. Consequently, the trainbrakes are not applied unless the vehicle speed is sufliciently high toremove the slidable sleeve 88 of the centrifugally-operated device 35away from the path of the escapement mechanism It will be appreciatedthat such lowspeed operation of thevehicle is thus permitted,irrespective of whether or not the track magnets 9 are successivelyenergized.

It will be seen that I have thus provided a system for automaticallystopping a car or train whenever the track ahead is occupied, orotherwise unsafe. However, although an alternating-current supply forthe track circuits is shown, the system may be operated withdirect-current energy, if desired. For the sake of simplicity, I haveshown the track circuits that are required with trafiic in only onedirection. and with protection for only one block head. However, thesystem may be readily adapted to any traffic requirements. and may beused in conjunction with present indicating. signal systems, the trackmagnets simply being connected in parallel relation to 1the clearcircuits of such indicating signa s.

Broadly considered, the system comprises the following combination ofapparatus:

1. A series of track magnets so located that their magnetic field mayinfluence suitable mechanism on the passing train.

2. Primary apparatus on the rolling stock, which is actuated by thetrack mag nets as the train passes.

3. Secondary apparatus on the rolling stock, which is so related to theprimary apparatus as to set the brakes on the train, provided the traintravels more than a certain distance and above a predetermined speedwithout passing an energized track magnet. Furthermore, if desired, theillustrated apparatus may readily be adapted to open the main orauxiliary cont-rolling circuits of an electric motor system, in additionto actuating the brake-valve.

owever, my invention is not necessarily restricted to the type ofapparatus shown, since, in some cases, it may be desirable to substituteWireless-telegraph apparatus in stations along the track for theillustrated track magnets, whereby wireless energy is utilized in lieuof a magnetic field. The analogy will be evident without'furtherdescription. Furthermore, the invention contemplates the use of anymechanism on the train that runs down after the train travels a certaindistance and, in so doing, stops the train; together with a resetting orrewinding of. such mechanism by means of stationary apparatus on or nearthe track, provided the stretch of track ahead is safe for travel.

From another aspect. the present system includes means having normaldanger characteristics, that is, the apparatus normally tends to set thevehicle brakes unless prevented by an external agency, viz., the

mecca? track magnets, although the track magnets are dcenergized, exceptwhen needed for this purpose.

Consequently, I do not wish to be restricted to the specific circuitconnections, structural details, or arrangement of parts herein setforth. as various modifications thereof may be effected withoutdeparting from the spirit and the scope of my invention. I desire,therefore, that only such limitations shall be imposed as are indicatedin the appended claims.

I claim as my invention:

1. An automatic train-stop system comprising a plurality of spacedandnormally deenergized track magnets, means dependent upon the proximityof the train for ener gizing said magnets, and means havingnormaldanger" characteristics for stopping the train comprising time-elementmechanism carried by the train and influenced toward its initialcondition by said magnets.

2. An automatic train-stop system comprising a plurality ofelectrically-insulated blocks and of spaced track magnets, meansdependent upon the presence of a train in a block for successivelyenergizing said magnets, and time-element means carried by the train andresponsive to magnetic impulses from said magnets for preventing theautomatic stoppage of the train.

3. An automatic train-sto system comprising a plurality ofelectrically-insulated blocks and of spaced track magnets, meansdependent upon the presence of a train in a block for successivelyenergizing said magnets, and time-element means carried by a train forarresting the movement thereof unless all track magnets passed by thetram are energized.

4. An automatic train-stop system comprising a plurality ofelectrically-insulated blocks and of spaced track magnets, meansdependent upon the presence of a train in a block for successivelyenergizing said magnets, time element mechanism carried by the train forautomatically stopping the movement thereof, and means impulsivelyinfluenced by said magnets for re-setting sald mechanism to preventtrain stoppage.

5. An automatic train-stop system comprising a plurality ofelectrically-insulated blocks and of spaced track magnets, meansdependent upon the presence of a train in a block for successivelyenergizing said magnets, means carried by a. train for arrestingthe-movement thereof unless all track magnets passed by the train areenergized. and means for preventing the complete operation of saidmovement arresting means when the vehicle speed is below a pr(determined value.

(3. An automatic train-stop system comprising a plurality of spacedtrack magnets. a brake-controlling device carried by the gagement withsaid device, a normally closed train, movable means inflneced by saidmagment with said device, and an escapement mechanism for effectingrelatively slow movement of said movable means.

7. An automatic train-stop system comprising a plurality of spaced trackmagnets, a brake-controlling device carried by the train, movable meansbiased toward operative engagement with said device and magneticallycontrolled from the track magnets in opposition to the biasing effect,and an escapement mechanism actuated in accordance with the-.train speedfor efiecting retarded response to said biasing effect.

8. An automatic train-stop system comprising a pluralit of spaced trackmagnets, a brake-controlling device carried by the train, movable meansbiased toward operative engagement with said device, an impulse coilenergized by passing the track magnets to actuate said movable'means inopposition to the biasing effect, and an esoapement mechanism drivenfrom the train Wheels for permitting intermittent response to saidbiasing effect.

9. An automatic train-stop system comprising a plurality of spaced trackmagnets, a brake-controlling device carried by the train, an operatingcylinder, a piston member therefor biased toward operative engagementwith said device, a normally closed valve for preventing access offluid-pressure to 'said cylinder, an impulse coil energized by passingthe track magnets for opening said valve to actuate the iston member inopposition to the biasing e ect, and an escapement mechanism driven fromthe train wheels for permitting retarded response to said biasingeffect.

10. An automatic train-stop system 'comprising a plurality of spacedtrack magnets, a brake-controlling device carried by the train, anoperating cylinder, a piston member therefor biased toward operativeenvalve for preventing access of fluid-pressure to said cylinder, animpulse coil energized by passin the track magnets, a relay device closeb such energization for effecting the opening of the valve to actuatethe piston member in opposition to the biasing effect, an escapementmechanism driven from the train wheels for effecting step-bystepmovement in response to said biasing efiect, and means dependent uponthe degree of movement for interrupting the energizing I circuit of saidrelay device.

11. An automatic trainstop system comprising a plurality of spaced trackmagnets, a brake-controlling device carried by the train, movable meansbiased toward operative engagement with said device and magneticallycontrolled from the track magnets in opposition to the biasing effect,an escapement mechanism actuated in accordance with the train speed foreffecting retarded response to said biasing effect, and means responsiveto the vehicle speed interposed in the path of said movable means toprevent such response beyond a predetermined stage.

12. An automatic train-stop system comprising a plurality of spacedtrack magnets, a brake-controlling device carried by the train, anoperating cylinder, a piston member therefor biased toward operativeengagement with said device, a normally closed valve for preventingaccess of fluid-pressure to said cylinder, an impulse coil energized bypassing the track magnets for opening said valve to actuate the pistonmember in opposition to the biasing e-ifect, an escapement mechanismdriven from the train Wheels for permitting retarded response to saidbiasing effect, and a centrifugally 0perated device interposed in thepath of said piston member to preventoperation of the brake controllingdevice under relatively low-speed conditions of the train.

In testimony whereof I have hereunto subscribed my name this 31st day ofMarch, 1919.

MAURICE F. JONES.

